Athermic glass or plastic windows which is best ?

Athermic glass doesn't insulate any better. It is basically laminated glass that has an additional ultrathin (transparent) coating of silver which reflects some of the sunlight. It has the same insulating characteristics of normal laminated glass but because it reflects an appreciable amount of heat, the inside of the vehicle will get less hot.

However, there have been a multitude of problems reported by owners with the use of toll tags and GPS equipment located on the inside of athermic windscreens, so that needs to be taken into account before purchase if one may be affected.

ps: You can't compare athermic glass with double glazing. Double glazing will provide insulation that is also effective in cold weather or when it's hot, but with an overcast sky. Athermic glass does not.have such properties. It will only help when the sun is shining in a more or less clear sky.

We have an AS PVC with glass windows in the hab unit. As I understand it, the windows are those of the Peugeot Boxer mini bus which is the base vehicle of the MH.

We've not noticed any insulation or condensation issues, not even in The Hebrides during Storm Hector. The windows are tinted so make the interior slightly dark which can be welcome in blazing sun but there is plenty of light from the Heki. From outside you cannot see in so they aid privacy. 

Be aware that usually the windows at the rear do not open and, in our case, only those behind the driver's seat (the kitchen) and in the sliding door can be opened. Lack of ventilation is overcome by opening the rear doors if necessary.

The big bonus is that the windows don’t collect scratches when you brush the hedge, unlike the plastic versions, and they offer more security.

We had an Autosleeper Warwick for four years (before returning to caravans after three motorhomes) it was a three season van, spring , summer, autumn, probably like a lot of PVC`s. Windows were`nt too bad but overall it was colder in my opinion, especially at the back where both doors were`nt fully insulated.  The windows are more inclined to condensation, if you were to engage in heavy duty cooking they would be running with water. The van had a diesel heater and blown air with no vents at the front and this was a very cold area. All in all they are a good idea but just not very good in the winter.

We don’t use it in winter other than for day trips so I can’t comment on that but I’ve not noticed any draughts and we have a Truma combi boiler for heating and we stay warm. The extractor hood has prevented condensation from cooking along with opening the kitchen window and/or the small Heki slightly. 

All told, we've found no difference in the windows from the plastic ones in our previous coachbuilt MH, other than as I described in my first post. The glass windows certainly wouldn’t put me off buying if all else was right.

We had them in our first Autosleeper, no problems and we also liked them for privacy. We had cold spots but I think AS have improved insulation since then. As TW says lack of openings is a slight drawback but you can open the roof lights etc. I felt they were more secure than the plastic ones which we have now in a slightly larger Autosleeper.

Autosleepers windscreen glass isn't athermic as far as I am aware, it's used in side and rear panels but not in the cab.

I think the cab glass is the standard Peugeot issue in our case, Brue.

You might notice a toll tag at the top of our windscreen and it works with no problems. 

Thanks TW.

I also found this information about athermic glass on the A/S web site. HERE

PS I must get out more, my Saturday nights aren't really exciting enough. I see the OP has asked the same question elsewhere. Hope we have been of help. 

Cheers, Brue. Yes, we've got all the bits mentioned.